CAM for Digital Joints

Hi everyone,

I want to build an enclosure for my Prusa i3 clone so that I can get a controlled environment to print ABS consistently, so I figured I’d fire up ye olde MPCNC and cut some panels with box joints.

I started laying out the box joints, but then stumbled on those nifty “50 Digital Joints” zip that floats around, and some of the joints are pretty nice. The problem is, they’re really 3D joints, and Estlcam (or maybe my ability) falls short when you try to setup toolpaths of weird overlapping cuts at different heights.

I found “FingerMaker!” through some googling, and that looks promising but I’m curious about two things: What kind of joints do you usually use for carcasse joining when cutting on the CNC, and secondly, what software do you use to create the toolpaths for those joints.


You can do them in estlcam, just takes a bit to wrap your head around them.

I zipped up the jigsaw frame joint below. I also found why my cut didn’t line up very well. When I opened it back up I found I didn’t scale it properly for my 1X2 test pieces. I just redid the paths so you can see how I did it. When I cut my parts I rotated each piece so the pointy end was facing me on my router, this way I could use the same hold down jig for both. I haven’t figured out how to make estlcam just cut a line, so I had to create a cutout box all the way around the end of one piece, and you’ll still need to clean up one spot with a chisel.

Oh, this is setup to cut with a 1/16" end mill. (51.7 KB)

Thanks for the reply, Barry! I was going to work on recreating the clip tenons or perhaps the hammer tenon joint because I’m joining 500milx500mil sheets of MDF into a cuboid carcasse. I can still go with the box joints, but, those digital joints sure look sexy.

I love the jigsaw joint – if I was doing a picture frame or something requiring 90 degree board joining, the jigsaw pattern looks like a fantastic choice.


Hey Barry,

What version of Estlcam did you use to make that file in the Zip? 9.018 says a newer version made the file; I jumped on, saw there was beta 9.028 and downloaded that, but now it is telling me the file format you used is too OLD.

No happy mediums in software development :slight_smile:


I had a breakthrough! I can use Estlcam’s ability to use layers to get this done – I just have to redraw the joint in several layers where I think through what needs a pocketing and what needs a through-cut, and I think I can get this hammer tenon down with minimal fuss.

EDIT: Attached the project file I’m about to take down to the machine! (7.45 KB)

You know. I forget which version I used! I have 4 different versions on my desktop. I found the latest beta explodes when trying to mill out text, but works great for pockets with islands. The older ones would explode on the islands.?

Photo album

First picture is my machine, next two photos are the attempt to cut the hammer tenons that I pasted above, and the final two pictures are box joints I cut on the CNC as well.

I have a suspicion that if I put some tolerance into the mortise piece of the hammer tenon set, I might be able to fit in. Even though they don’t fit, it’s a success for me because it proved that the pocketing technique more-or-less was the way to go when having to do 2.5d joinery work.

Sadly, this is taking so much longer than me just knocking the joints out on a table saw…

Estlcam has a function to put a little divot on the inside corners so joints like this will fit. It’s called corner overcuts. Some stuff will always be faster with hand tools, but if you’re making a bunch of one thing that’s where cnc comes in handy.